The present invention relates to a treatment device for subjecting an object to a desired treatment after washing the object, a laser annealing device for annealing an object by laser irradiation, a manufacturing apparatus provided with the treatment device or the laser annealing device, and a manufacturing apparatus for a flat display device.
In manufacturing processes for manufacturing an array substrate of an liquid crystal display panel for use as a flat display device, such as a film forming process, etching process, laser annealing process, etc., substrates are washed before pretreatments in order to secure the cleanness of the substrates, in general. To attain this, a manufacturing apparatus comprises a plurality of treatment devices for carrying out the individual processes and a washing device provided independently of the treatment devices. The substrates, to-be-treated objects, are transported between the washing device and the treatment devices by means of a truck or an AGV (automatic transportation vehicle) in a manner such that they are set in a cassette.
In the case where the treatment devices and the washing device are arranged separately, however, the entire manufacturing apparatus requires a wide installation space, and the substrates are transferred between the devices. Therefore, the transportation takes so much time that the substrates may possibly be soiled and the lead time is long.
Further, the treatment time or Q-time requires management, and introduction of the substrates into each preceding stage is restricted by conditions for each succeeding stage, so that the processing operation of the manufacturing apparatus is complicated as a whole.
In a known laser annealing device for the laser annealing process, a laser is applied to non-single crystalline (amorphous) silicon film formed on a substrate to anneal the silicon layer, thereby forming a polycrystalline silicon film. If the annealing process is carried out in an ambient atmosphere with a high oxygen concentration, for example, in the laser annealing device, the resulting polycrystalline silicon film may possibly be poor in properties.
To avoid this, a novel annealing device is developed and described in Jpn. Pat. Appln. KOKAI Publication No. 9-275080, for example. This device is designed so that a substrate inlet chamber, transfer chamber, annealing chamber, transfer chamber, and substrate outlet chamber are connected in succession by means of gate valves. In this device, a vacuum atmosphere or nitrogen atmosphere is defined in an annealing chamber by means of a vacuum exhaust system. In the annealing chamber, substrates are preheated and irradiated with a laser for annealing.
In the laser annealing device constructed in this manner, however, the vacuum exhaust system is needed to control the atmosphere in the annealing chamber, so that stabilizing the atmosphere takes a lot of time, and each chamber must be composed of the so-called vacuum chamber that is highly airtight, thus entailing an increase in manufacturing costs. Since a large number of chambers are connected in the device, moreover, the device is large-sized, and use of increased transportation mechanism parts for connecting the chambers and transporting substrates results in an increase in number of spots where particles are produced. If laser irradiation is carried out with impurities, such as boron, phosphorus, etc., adhering as particles to the substrates, the characteristics of formed transistors are adversely affected. In applying a laser to the substrates in the vacuum atmosphere or nitrogen atmosphere, moreover, the crystal grain size of non-single crystalline silicon is reduced and the mobility of the transistor characteristics is lowered unless the oxygen concentration of the atmosphere is adjusted to a given value. Furthermore, large quantities of gases are needed to define a predetermined atmosphere, such as a nitrogen atmosphere, in a large-sized chamber for preheating, as well as for annealing, thus entailing an increase in manufacturing costs.
The present invention has been contrived in consideration of these circumferences, and its object is to provide a treatment device capable of preventing contamination of a to-be-treated object and shortening the treatment time, a laser annealing device designed to improve the quality of laser annealing and reduce the manufacturing costs, a laser annealing method, a manufacturing apparatus provided with the treatment device or the laser annealing device, and a manufacturing apparatus for a substrate of a flat display device.
In order to achieve the above object, a treatment device according to the present invention comprises: a stage section carrying a to-be-treated object thereon; a treatment section opposed to the stage section, for subjecting the object to a predetermined treatment; a washing section for washing the object, the washing section being located near to the stage section and the treatment section and deviated from a space between the stage section and the treatment section in a second direction crossing a first direction passing through the stage section and the treatment section; and a transportation mechanism arranged between the stage section and the treatment section for transferring the object between the stage section, treatment section, and washing section and loading the object, washed in the washing section, directly into the treatment section.
According to the treatment device constructed in this manner, the washing section and the treatment section are located adjacent to the stage section, so that the movement of the to-be-treated object can be reduced. In particular, the object washed in the washing section can be loaded directly into the treatment section, so that contamination of the object can be prevented, and the treatment time can be shortened. Since the washing section is situated across the direction of transportation of the object to the treatment section, moreover, the treatment device can be prevented from being unduly elongated in the direction in which the object is loaded into and unloaded from the treatment section.
According to the invention, moreover, the treatment section includes a transportation portion located adjacent to the stage section and one or more individual treatment portions located adjacent to the transportation portion. Thus, the time for the movement of the to-be-treated object can be shorted, and one or more treatments can be carried out for the one washing section.
For example, a treatment device for an excimer laser or a film forming chamber for chemical vapor deposition for forming a non-single-crystalline silicon film is provided as the individual treatment portion.
A laser annealing device according to the invention comprises: an annealing chamber storing a to-be-treated object in a manner such that an atmosphere surrounding a laser irradiation region of the object is kept at a pressure not lower than the atmospheric pressure; laser irradiation means for applying a laser beam to the laser irradiation region of the object stored in the annealing chamber, thereby subjecting the object to laser annealing; and transportation means for loading the object directly into the annealing chamber.
The laser annealing device further comprises a stage section opposed to the annealing chamber and carrying the to-be-treated object thereon and a washing section located adjacent to the stage section and the annealing chamber, for washing the object, and wherein the transportation means includes a transfer robot for transferring the object from the stage section to the washing section and loading the washed object from the washing section directly into the annealing chamber.
Moreover, a method of laser annealing a to-be-treated object according to the invention comprises the steps of: loading the object into an annealing chamber; and annealing the object in the annealing chamber by applying a laser to a laser irradiation region of the object in a manner such that an atmosphere around the laser irradiation region is kept at a pressure not lower than the atmospheric normal pressure.
According to the laser annealing device and the laser annealing method described above, the object can be loaded directly into the annealing chamber, so that transportation mechanism parts between component units can be reduced in number. Thus, sources of particles can be reduced to ensure annealing in a stable atmosphere. In consequence, the quality of the treatment of the object can be improved. Further, laser annealing is carried out in an atmosphere at a pressure not lower than the atmospheric pressure, so that there is no need of a vacuum pump or the like. Thus, the construction is simplified, and therefore, the manufacturing costs can be reduced.
Since the washing section is located adjacent to the annealing chamber, moreover, the to-be-treated object can be transported to the annealing chamber without delay after pretreatments for annealing in the washing section. Accordingly, annealing can be effected in a manner such that particles are removed, and that non-single-crystalline silicon is prevented from natural oxidation or impurities, such as boron, phosphorus, etc., are removed and prevented from adhering to the object. Thus, the quality of the object is improved.
According to the invention, furthermore, an atmosphere separating cover that surrounds the laser irradiation region of the to-be-treated object is arranged in the annealing chamber, and gases are supplied to the inside of the cover by means of gas supply means. By doing this, the necessary atmosphere portion for annealing in the annealing chamber can be controlled with ease. Thus, the construction of the laser annealing device can be simplified to reduce the gas consumption and therefore, lower the manufacturing costs.
Moreover, the gas supply means includes detecting means for detecting the atmosphere inside the atmosphere separating cover and gas control means for controlling the gas to be supplied to the space inside the atmosphere separating cover. Therefore, annealing can be effected in a desired atmosphere, so that the quality of the to-be-treated object is improved.
A substrate having a thin film thereon is used as the to-be-treated object, and an excimer laser capable of changing the film quality is used as the laser. Accordingly, a non-single-crystalline silicon film can be suitably formed on a glass substrate, for example.
A to-be-treated object of a desired quality can be obtained by loading the annealing chamber with a nitrogen atmosphere. In this case, the oxygen concentration of the atmosphere in the chamber is adjusted to 0.1% to 13%, preferably 1.0% to 7.0%.
A manufacturing apparatus according to the invention comprises: a transportation device for transporting a to-be-treated object along a predetermined transportation path; and a plurality of treatment devices arranged along the transportation path, for individually subjecting the object transported by the transportation device to predetermined treatments. At least one of the treatment devices includes a stage section carrying thereon the object transported by the transportation device, a treatment section opposed to the stage section for subjecting the object to a predetermined treatment, a washing section for washing the object, the washing section being located near to the stage section and the treatment section and deviated from a space between the stage section and the treatment section in a second direction crossing a first direction passing through the stage section and the treatment section, and a transportation mechanism arranged between the stage section and the treatment section for transferring the object between the stage section, treatment section, and washing section and loading the object, washed in the washing section, directly into the treatment section.
In the manufacturing apparatus described above, the first direction is perpendicular to the transportation path, and the second direction is substantially parallel to the transportation path.
Furthermore, a substrate manufacturing apparatus according to the invention comprises: a transportation device for transporting a substrate along a predetermined transportation path; and a plurality of treatment devices arranged along the transportation path, for individually subjecting the substrate transported by the transportation device to predetermined treatments. At least one of the treatment devices includes a stage section carrying thereon the substrate transported by the transportation device, a treatment section opposed to the stage section for subjecting the substrate to a predetermined treatment, a washing section for washing the substrate, the washing section being located near to the stage section and the treatment section and deviated from a space between the stage section and the treatment section in a second direction crossing a first direction passing through the stage section and the treatment section, and a transportation mechanism between the stage section and the treatment section for transferring the substrate between the stage section, treatment section, and washing section and loading the substrate, washed in the washing section, directly into the treatment section.
Additional objects and advantages of the invention will be set forth in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. The objects and advantages of the invention may be realized and obtained by means of the instrumentalities and combinations particularly pointed out hereinafter.